1. Field of the Invention
The present invention relates to an imaging device and an image processing apparatus. More specifically, the present invention relates to an imaging device which electronically performs a camera shake correction, and an image processing apparatus which performs image processing, such as a camera shake correction, a noise reduction, etc. on a plurality of object scene images according to a time series that are captured by the image sensor.
2. Description of the Related Art
(I) In relation to imaging devices of such a kind, in one related art, a still image is produced by displacing a plurality of images being continuous according to a time series and adding them to each other. In another related art, a motion image is produced by displacing and clipping a part out of each of the plurality of object scene images being continuous according to a time series.
In general, in an actual imaging device, such as a digital camera, etc., it is required to shoot both of the motion images and the still images with high image quality. However, even if the related arts are merely combined, it is difficult to shoot both of the motion images and still images with a proper exposure amount by accurately using two kinds of camera shake correction for motion image and still image.
(II) With respect to the image processing apparatus of such a kind, in one related art, by displacing and cutting a part from each of a plurality of object scene images being continuous according to a time series, a motion image with small movement among the object scene images due to a camera shake (movement component in a time axis direction) is produced. In another related art, a data for correction to correct an FPN (Fixed Pattern Noise) of the image sensor is stored in a memory, and a correction processing unit performs on the object scene image output from the image sensor FPN correction processing on the basis of the data for correction. In a still another related art, by displacing a plurality of object scene images being continuous according to a time series and making an addition to each other, it is possible to suppress a random noise of each object scene image (3DDNR: Three-Dimensional Digital Noise Reduction).
Generally, in an actual image processing apparatus, such as a digital movie camera, etc., a movement due to a hand shake, a random noise and an FPN are required to be suppressed. However, merely combining the related arts with each other requires more memory and increases power consumption.
(III) Out of the image processing apparatuses of this kind, with respect to the one performing a 3DDNR, in one related art, by displacing a plurality of object scene images being continuous according to a time series and performing a weighted addition on them, a random noise of each object scene image is suppressed. In making the weighted addition, a coefficient to be multiplied by each object scene image is changed depending on the magnitude of the movement among the object scene images. The magnitude of the movement among the object scene images is determined in unit of the object scene image (frame or field). In another related art, the magnitude of the movement is determined in unit of the pixel, and the 3DDNR is performed on only the part with small movement within each object scene image.
However, in the former related art, in a case that an object (hit ball, etc.) which is smaller in size and quickly moves is included in the object scene, the image at the object portion is blurred due to the 3DDNR. On the other hand, in the latter related art, the 3DDNR is performed only on the part with small movement, and therefore, the blur at the portion with large movement is avoided, but the dimension of the movement is determined by the unit of pixels, resulting in an enormous amount of throughputs.